Hercule Poirot boards the famous Orient Express train in Istanbul as it makes it's way towards London, along with many glamorous international passengers. A ruthless American businessman on board asks Poirot to watch his back but Poirot refuses. When Poirot wakes up the following morning he learns that the train is stuck in a snowdrift and the businessman is dead. With the train completely cut off Poirot finds himself investigating the murder.